Chen Yongzheng, a delivery boy, accidentally fell into a valley and was seriously injured. He thought he would die. Fortunately, he was saved by an old man living in the valley and he survived.
The old man saw that Chen Yongzheng was an upright man with strange muscles and bones, so he taught him Qimen Dunjia, divination and medical skills. After he completed his studies, the old man told Chen Yongzheng about the devil and the immortal.
Chen Yongzheng went down the mountain to find the devil, kill the devil, and save the world.